Experiences and Benefits with Substation Automation and Protection Schemes Based On IEC 61850

IEC 61850 as an acceptable universal standard has been currently widely practiced by utilities across the world due to discrete features like interoperability, interchangeability, expandability, future proof and to facilitate flexible data communication. It is widely used in India since almost last five years.

In order to grab the benefits of technological advancement in communication technology of IEDs and Substation automation, GETCO has initiated implementation of IEC 61850 based SAS since 2008. More than 20 substations are now commissioned with IEC 61850 based SAS with Yard Kiosk concept.

Lot of ground work has been carried out right from selection of philosophies, standardization of schemes, Soft logics etc. for implementing IEC 61850 based SAS. Over a period of time, on the basis of experience and confidence in technology more and more IEC 61850 configuration applications are being implemented in phase manner to achieve enhanced, reliable and better configured Substation Automation System.

During actual implementation of IEC 61850 based SAS, many challenges and issues are being faced for Soft logic configuration, GOOSE configurations, Soft protection signal configurations, HMI Graphics and Remote Control.

These issues are addressed iteratively to have long lasting solutions. For this, (i) HMI graphics are prepared and standardized to stream line signal lists and configuration processes thereof. (ii) Logic of PT selection scheme (3 Bus) & N-I-T are also rederived and representation in drawing is updated as per actual configuration logic to be configured in SAS instead of conceptual logic. (iii) FAT/SAT procedures are being updated to include all specific tests like specific GOOSE logics for - Trip Transfer, PT selection, Carrier tripping. Also Soft protection signals are included as part of drawing to avoid configuration discrepancies.

There is no doubt that, IEC 61850 based SAS is dependable and sustainable technology which will drive the power industry towards future needs. But, much work is required to be carried out in terms of standardization in Configuration methodology (i.e. System engineering, creation of SCD files, GOOSE configuration etc). Also SCADA software is vendor specific and hence dependency is still on system provider for future extensions. Last but not the least, building up of competence level at system provider as well as user side is required to optimize benefits of IEC 61850 based SAS in real sense.

This paper shares experiences of implementation of IEC 61850 based SAS, Issues & Challenges faced and improvements for better commissioning and thereby better performance of overall system.